I used dead rock in my return to the hobby.  I wanted to get back in without the huge expenses so I recycled.  It took about two months for the pods, worms etc. to populate the tank.  It has been about 6 months and the coralline is finally growing well but my lighting was to blame for that I think.
I cleaned the rock, baked it (literally 450 deg for two hours) then baked it in buckets of salt water for a month.  I baked it the first time to insure that the uncontrollable turf algae would never return.  Most people get cute little hair algae, I had coarse Astroturf that drove me out of the hobby.
I set up the tank with the dead rock, new sand, and a couple pieces of rubble from the LFS and cycled it.  I added blue leg hermits and fed them for another month.  I added a couple of mushrooms on more rubble to test the waters.  Then very slowly added more corals.  I had a minor diatom issue but that is it.  No hair algae at all.  I have no fish but do feed my sun polyps heavily with no issues so the rock is again live.
I have to be honest, the tank looks like sh**.  It gets better every day thou.